psyco_1322 Posted July 27, 2007 Posted July 27, 2007 Ok, Ya I know how to do percentages fine but when you had the +% I didnt know if that was 8% more than the can says to use with the catalysty or if it was additional to the ammount of comp. So denatured methOH is just denatured alcohol? I should be able to use just straight methyl shouldnt I? I dont have any denatured, did but it turned into rusty denatured after it jrusted out the inner of the can. But I have a lot of methyl since I like playing with methyl borate. But just to make sure im right: If you have 15% NC lacquer then that means it would have 15 parts NC for every 100 parts acetone correct? And if you thinned that 15% say with 5% acetone than you would have 3% lacquer. And that would mean that you would need an additional 500 parts acetone. The thinning of the percentages is what gets me sometimes. Im probably wrong but if you dont know than you either learn or keep going not knowing it. If I dont know about somehting than I dont do it. I do though try to find out what im doing first. Anyways......Thanks for the help. To bad out of all those chems I only have bright Al.
psyco_1322 Posted August 2, 2007 Posted August 2, 2007 I had them comets laying around for a few days and they were just magnalium slivers in bp, binded with R. But they started to have the magnalium poking out and it looked like it might have been reacting with the magnalium causing it to oxidise and expanding until they popped out a bit. Every experienced that? Ok update. Got my bp and was gonna shoot those two I made last ninght when I got home. The 1.25 comet was all cracked to hell and crumble apart. It burnt fine though. The 1.75 comet, I wrapped with craft a day before and Im thinking thats what saved it. But it was a bit worse than the day before too. I shot it but it broke in half mid air. <Which I expected it to do anyways. Guess The Magnalium either needs coating or my comets dont have much of a shelf life.
Pretty green flame Posted August 23, 2007 Posted August 23, 2007 qwezxc12, i have a question. I can't find anything called Resorcinol glue localy, and i'm not too keen on ordering from abroad, but the closest i came to resorcion glue is something called Phenol-Formaldehyde glue. Do you think this is the same stuff? Cheers
FrankRizzo Posted August 23, 2007 Posted August 23, 2007 The product you might find at a hardware store is DAP-brand Weldwood Waterproof Resorcinol Glue. Or, if you have any local places that restore old wooden aircraft, they will have it by the name Cascophen (or G1131).
qwezxc12 Posted August 23, 2007 Author Posted August 23, 2007 qwezxc12, i have a question. I can't find anything called Resorcinol glue localy, and i'm not too keen on ordering from abroad, but the closest i came to resorcion glue is something called Phenol-Formaldehyde glue. Do you think this is the same stuff? CheersI think that they are similar but not identical; I saw many woodworking articles referring to either resorcinol or phenol catalyzed glues. Resorcinol resin is catalyzed with para-formaldehyde, either in the form of a powder mixed with wood dust (in the case of the DAP product) or a second liquid in the case of Cascophen as FrankRizzo mentioned.http://www.aircraftspruce.com/catalog/graphics/02-00036.jpg You can buy that stuff from Aircraft Spruce. They do have Europe / UK reps and ship globally. Some type of phenolic resin has been thought to be used for binding Chinese Dragon's Egg granules according to posts on Passfire and Re.pyro. I bet it would work fine for comets. If you try it out, read the MSDS for potential incompatibilities and hazards, work in small test batches until you get a feel for it, and figure out the proper thinning ratio and solvent to get the working time and binder consistency you want. Good luck.
Pretty green flame Posted August 24, 2007 Posted August 24, 2007 The product you might find at a hardware store is DAP-brand Weldwood Waterproof Resorcinol Glue. Or, if you have any local places that restore old wooden aircraft, they will have it by the name Cascophen (or G1131). Frank, you make it sound so easy but unfortunately every hardware store i've been has never even heard of the stuff and wooden aircraft restoration places are non-existant here. qwezxc12, I've asked my dad for a sample to bring home from work so i'll give it a try with the phenol-formaldehyde glue. Also, i've checked out Aircraft Spruce, this will probably be a last resort as I don't quite feel like paying a killer ammount of shipping I'll report back with some results from the phenol-formaldehyde glue, if it works it might be an alternative for those who cant find resorcinol glue. Cheers
psyco_1322 Posted August 28, 2007 Posted August 28, 2007 The product you might find at a hardware store is DAP-brand Weldwood Waterproof Resorcinol Glue. Or, if you have any local places that restore old wooden aircraft, they will have it by the name Cascophen (or G1131).Frank, you make it sound so easy but unfortunately every hardware store i've been has never even heard of the stuff and wooden aircraft restoration places are non-existant here. qwezxc12, I've asked my dad for a sample to bring home from work so i'll give it a try with the phenol-formaldehyde glue. Also, i've checked out Aircraft Spruce, this will probably be a last resort as I don't quite feel like paying a killer ammount of shipping I'll report back with some results from the phenol-formaldehyde glue, if it works it might be an alternative for those who cant find resorcinol glue. Cheers Go to an ace hardware store, they can order it for you if its not in stock.
Pretty green flame Posted August 28, 2007 Posted August 28, 2007 Hmm...yeah, that's a solution, or atleast it would be if i wasn't located on the other side of the globe
qwezxc12 Posted August 28, 2007 Author Posted August 28, 2007 Well, I found out that adding a 1/2in core *and* milling the BP makes my 3in greenmix/Mg turnings comets self-destruct about halfway up...nice effect as they sort of CATO into a cloud of burning magnesium, but unexpected. These are the cored 3in comets:http://www.apcforum.net/files/IMG_2.jpg The core tooling will probably help slower burning comps, but with the Greenmix/Mg it seems to be the case of either milling or coring the comet.
psyco_1322 Posted September 2, 2007 Posted September 2, 2007 Have you let one of your comets set around for awail? Say like a week to see if they are satble fro storage? Is that magnesium coated? My magnalium wasnt and in a few days the comets fell apart after the magnalium got a bad oxide layer from being with the nitrate.
qwezxc12 Posted September 3, 2007 Author Posted September 3, 2007 Have you let one of your comets set around for awail? Say like a week to see if they are satble fro storage? Is that magnesium coated? My magnalium wasnt and in a few days the comets fell apart after the magnalium got a bad oxide layer from being with the nitrate.Both times I've made batches of 3in comets they've sat for 5 and 9 days prior to shooting. The resorcinol is thinned with either meth or eth alcohol so there is only a very small % of water present in the mix. I've had no problems with the Mg decomposing (heat or ammonia odor)
psyco_1322 Posted September 3, 2007 Posted September 3, 2007 Well mine didnt heat up or smell just started expanding and getting kinda crusty on the outside and easier to crumble apart. I thinned mine with methanol. The bigger 1.75" one I wrapped with paper and it stayted together better than the 1.25" one. < That one fell completely apart. Looked like the Magnalium had a oxide layer on it after it crumbled. Still gave off white sparks though. Ill try again and see what happens. Maybe it was teh climate?
mormanman Posted September 13, 2007 Posted September 13, 2007 I don't think that we've established this but I recently figure out you don't need a press to make cakes/comets. You can ram or tap or whatever method you need in to a cup or something and make it like a sand castle (the kind you put the sand in a flip it over; then tap it and out comes the sand castle but in this case comet.)
Mumbles Posted September 13, 2007 Posted September 13, 2007 Thats going to result in very weak comets, especially at larger sizes. So no, you can't make comets in that method.
mormanman Posted September 13, 2007 Posted September 13, 2007 What about crossettes (don't think I spelled that right.)
mormanman Posted September 13, 2007 Posted September 13, 2007 PISS. My plot has been foiled again. That sucks. By the way just now figure out why no crossettes. That blows.
asilentbob Posted September 13, 2007 Posted September 13, 2007 On the note of comets... which i still haven't got around to trying my hand at... despite my sexy 3/4" crossett tooling... I'm eventually going to get a 26.5mm flare gun (probably German) and reload the shells to test comets out of... Nifty nifty! Will likely need a sleeve for good fit... Just gotta make sure that nothing gets stuck in the barrel... !
Bonny Posted September 13, 2007 Posted September 13, 2007 I've made some comets by ramming into a toilet paper tube. the problem is they can't be rammed very hard so some (depending on the comp) tend to be blown apart by the lift charge creating a mine effect. Small comets (1") can be successfully made by ramming comp (not shock sensitive) in a stainless pipe with a wood plunger. A few good hits with a hammer and then pump out the comet. Works fine for me.
frogy Posted September 13, 2007 Posted September 13, 2007 Last night I rammed some of my 3/8" by 2" tubes about 1/2 full of Chrysanthemum #8 and Tiger Tail just to test it and they looked great... Got dextrin, perchlorate, benzoate, red iron oxide, stront nit (I hope), bentontite, and some other chemicals today...
qwezxc12 Posted September 14, 2007 Author Posted September 14, 2007 FWIW, all of the 2in comets I've made (1.5" OD) are rammed...three or four hard blows with a hard rubber mallet. Basically until the comp stops compacting...and the 2in comets are shot "naked", with no re-enforcement and hold together fine. I lift them fairly hard: the comets weigh in ~50g and I lift them with 10-12g of fairly fine BP - whatever I sift that passes a 16mesh screen. The 3in comets are pressed, and those get three or so turns of 30lb craft broken in with paste + plus a 2.5" chipboard end-disk for support on the lift side... I also lift those a little on the hard side. Un-cored they weigh ~300g and they're lifted with 50g or so.
Mumbles Posted September 14, 2007 Posted September 14, 2007 I never said that they can't be rammed or whatnot. I ram all my comets up to 1", mostly because I don't make any bigger ones yet. But the way Mormanman was describing it, would result in very weak comets and would definatly disintegrate upon lift/break.
psyco_1322 Posted September 14, 2007 Posted September 14, 2007 Last night I rammed some of my 3/8" by 2" tubes about 1/2 full of Chrysanthemum #8 and Tiger Tail just to test it and they looked great... Got dextrin, perchlorate, benzoate, red iron oxide, stront nit (I hope), bentontite, and some other chemicals today... My gosh someome else besides me does use C-8! You werent at the convention where you? I would have loved to choked that master shell builder Freeman after he massacred my shell description. He was basically saying wtf is C-8? A prime or something? Oh ya I list my primes on the shell description. Anyways.....Bob I got some of those silk parachute from Ned a the convention. Was goin to make ariel flares but not sure what to shoot them from, maybe use your gun come next year? Think ill use the red lance formula that Bill and Randy where using for delay.
frogy Posted September 14, 2007 Posted September 14, 2007 I love C-8... It has worked good for comets for me, and right now I have some cut stars drying... I think it looks great in shells... Lol "master" shell builder... and he doesn't know the most basic of charcoal stars... C-6, C-8, Willow, TT, and CoM... I don't like Crys of mystery very much though... It looks much better in real life than on films though
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